Optimization of the thermally oxidized 4H-SiC MOS interface has produced p-channel
lateral MOSFETs with hole inversion layer mobility as high as 10 cm2/Vs. This has been
accomplished by identifying the 1200oC Dry, 950oC Wet (un-nitrided) oxidation as ideal for hole
conduction across the MOS inversion layer and by implant activation annealing at 1800oC of the
heavily implanted n-type well. High temperature measurements show that the high mobility and
normally-off operation is maintained throughout the operating temperature range. Oxide leakage
measurements yield a dielectric strength of 8.5 MV/cm with 90% yield, thereby enabling the
manufacture of high performance p-channel devices like the IGBT.